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Essential guide

How to obtain an FNMT digital certificate with your new DNI

Choose DNIe, in-person accreditation or the mobile app, download the FNMT certificate and protect its backup.

Reviewed on 27 August 2026Official sources verified

The FNMT citizen certificate is a file linking your identity to a signing key. It is not the same as the certificates stored on the DNIe chip: it is requested, installed, backed up and revoked separately.

Information reviewed on 27 August 2026. FNMT offers video identification, in-person accreditation, DNIe and mobile-device routes. Technical conditions, video cost and participating offices can change; always start from the official FNMT site.

1. Check your starting point

Apply using the exact details on the new DNI, not the former NIE. Check the number, first surname and email before sending. If the DNI includes corrected or changed surnames, enter them exactly as printed.

If an NIE-based FNMT certificate still exists, use it only while valid and needed to close open procedures. A new certificate does not migrate cases or alter data held by each organisation.

2. Choose the right route

With an active DNIe

If the DNIe is valid, you know the PIN and have a compatible reader —or an Android NFC setup accepted by FNMT— you can identify yourself without visiting an office. Install the official software first, authenticate with the DNIe authentication certificate and sign when requested with its signing certificate.

With in-person accreditation

The official flow has four steps: preparation, online request, office accreditation and download. A request code arrives by email. Check whether your chosen AEAT, Social Security or other registration office requires an appointment, and bring the valid DNI.

With the mobile app

The FNMT app supports request, accreditation and download. Depending on current options, identity can be checked with DNIe, in person or by video. FNMT currently publishes a €2.99 plus tax charge for video identification; the certificate itself is free. Confirm the amount in the app.

3. Prepare the device before applying

Install only the configurator linked from the FNMT site. On the computer route, keep the same computer, browser and operating-system user from request through download. Removing profiles, reinstalling the system or switching browsers can make the generated private key unavailable.

Keep the request code and the password created during the process. FNMT warns that the password cannot be recovered; losing it before download means starting a new request.

4. Prove identity and download

For in-person accreditation, show the DNI and request code. FNMT says download is normally available about one hour after accreditation. The DNIe route is also enabled once the request is processed.

Enter DNI, first surname and code exactly as requested. Verify that the certificate appears in the browser or system store, then test identification on an official site without submitting a real procedure.

5. Create a backup

Export the certificate with its private key as .p12 or .pfx and protect it with a long, unique password. A copy without the private key cannot sign.

Keep at least one encrypted copy away from the computer and separate from the password. Do not send the file by email, messaging or shared cloud storage. Install it only on trusted devices and remove temporary copies.

6. Manage the former NIE certificate

Do not assume it is automatically revoked when requesting under another identifier. Check its status with FNMT’s official tool. Once receipts are saved, required access is closed and the DNI certificate works, revoke the former certificate if it remains active and should no longer be used.

Revocation is final and invalidates the certificate before its expiry. Keep proof, and do not confuse FNMT revocation with changing the DNIe PIN or chip certificates.

Common problems

  • Request not found: recheck DNI, first surname, code and completed accreditation.
  • Download fails: use the same computer, browser and user as the request.
  • Signing fails: confirm the backup includes the private key and the signing app can see it.
  • NIE appears: the old certificate was selected or the organisation has not updated its record.
  • DNIe blocked: resolve its PIN and certificates separately; FNMT is independent.

Ready when

  • The request contains the correct DNI and surnames.
  • Identity was accredited through an official route.
  • The certificate is installed and shows as valid.
  • A test login works with the DNI.
  • An encrypted, recoverable .p12 or .pfx backup exists.
  • The former NIE certificate was reviewed and revoked when appropriate.
  • Codes, passwords and backup files are not stored together.

Next step

Test access to AEAT, Social Security and Carpeta Ciudadana without submitting anything. Check which certificate is selected and that the service shows the DNI before a real transaction.